CN116997734A - Speed change mechanism - Google Patents

Abstract

A speed change mechanism is provided which enables a phase of a drive wheel to be adapted to a chain or a toothed belt by setting the drive wheel to a rotation permission state during a speed change operation. The speed change mechanism (1A) is configured in such a manner that it comprises: a main shaft; a first disk group and a second disk group (7A, 7B) each including a first disk and a second disk (10A, 11A, 10B, 11B) disposed in close proximity to each other in an orthogonal manner to the main axis; and a composite transmission wheel (S) comprising a plurality of transmission wheels (18) and a plurality of guide rods (9), wherein the transmission wheels (18) comprise chain wheels or pinions, the speed change mechanism (1A) can change the radius of the composite transmission wheel (S) to change speed, at least one clutch mechanism (21, 22) capable of switching each transmission wheel (18) into a rotation prohibition state and a rotation permission state is arranged, each transmission wheel (18) is set into the rotation permission state during speed change operation and each transmission wheel (18) is set into the rotation prohibition state during speed change operation.

Description

Speed change mechanism

Technical Field

The present invention relates to a speed change mechanism in which a plurality of small diameter sprockets are arranged on a circumference, both ends of a sprocket shaft are supported at intersections of a plurality of radial slits formed in a first disk and a second disk that are in close proximity, respectively, and a rotational phase of the second disk with respect to the first disk is changed, thereby changing a radius of a composite sprocket.

Background

Patent document 1 discloses a continuously variable transmission mechanism configured in such a manner that: the device comprises a main shaft, a first disc group and a second disc group respectively comprising a first disc and a second disc which are arranged in an orthogonal way with the main shaft, a plurality of first radial slits and second radial slits respectively formed on the first disc and the second disc, and three chain wheels and six guide rods supported by the crossing parts of the first radial slits and the second radial slits in the first disc group and the second disc group, wherein the radius of a compound chain wheel comprising the three chain wheels and the six guide rods can be changed to change the speed by changing the rotation phase of the second disc relative to the first disc.

The sprocket is also set to the rotation prohibiting state at the time of the shifting operation, and therefore the phase of the sprocket is not aligned with the chain at the time of the shifting. Therefore, a mechanical rotation driving mechanism is provided that sets the rotation phase of the sprocket during the shift operation. In the rotation driving mechanism, pinions are respectively fixed to shaft ends of two of three sprockets, a rack member is provided along a movement path of the pinions in a radial direction, and rotation phases of the sprockets are set via the rack pinion mechanism when the sprockets move in the radial direction at the time of gear shifting. However, the two pinions are set so as to rotate in opposite directions to each other.

Patent document 2 discloses a continuously variable transmission mechanism which is the same as that of patent document 1 and employs a sector gear member and a support portion that supports the sector gear member instead of a sprocket. In the continuously variable transmission mechanism, a play allowance mechanism capable of making the sector gear member play within a predetermined range is provided with respect to the support portion, and the sector gear member is pushed to the reference phase by the gear energizing member.

In the continuously variable transmission described in patent document 3, a plurality of slide members are provided so as to be movable in the radial direction along a plurality of radial grooves formed in a pair of discs, a sprocket is attached to the slide members, a screw is screwed into a female screw hole of the slide members, a power distribution mechanism for simultaneously rotating and driving the plurality of screws is provided so as to move the plurality of slide members in the radial direction, and a reverse rotation preventing mechanism such as a one-way clutch that allows rotation in only one direction is provided to each of the sprockets.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2015-178874

Patent document 2: WO2017/094404 publication

Patent document 3: japanese patent laid-open publication No. 2002-250420

Disclosure of Invention

[ problem to be solved by the invention ]

In the transmission mechanism of patent document 1, since the sprocket is also in the rotation prohibited state during the shifting operation, a mechanical rotation driving mechanism is provided that sets the rotation phase of the sprocket during the shifting operation.

However, in the rotation driving mechanism, since the two sprockets are rotated in opposite directions, not only tension or compression force acts on the chain, but also one sprocket rotates in a direction opposite to the moving direction of the chain, and thus a large shift operation force is required, and the shift operation mechanism is enlarged.

In the play tolerance mechanism of patent document 2, the tolerance range of the phase difference of the sector gear member cannot be increased to a minimum required, and thus the speed cannot be changed significantly in a state where rotation is stopped. Therefore, it is difficult to cope with the occurrence of an abnormality on the power source side or the output side.

Further, when a load torque is applied, a large force is required for performing a shifting operation, which deteriorates efficiency, and a force is also required for maintaining a gear ratio.

Moreover, since the phases of the sector gear members are misaligned at the moment the chain is meshed with the sector gear members, many impact sounds are often generated.

In the continuously variable transmission of patent document 3, the speed change can be performed by the one-way clutch, and the fixed clutch is used for response during reverse rotation or engine braking, but the rotation of the sprocket is prohibited by the clutch during reverse rotation or engine braking, so that the speed change operation cannot be performed during reverse rotation or engine braking. Further, patent document 3 does not disclose a specific structure of the clutch at all.

The present invention provides a speed change mechanism which enables the phase of a driving wheel relative to a chain or a toothed belt to be adapted by setting the driving wheel to a rotation permission state during a speed change operation, and a speed change mechanism which is provided with a locking mechanism for firmly locking the driving wheel in a manner of preventing the driving wheel from moving in the radial direction during the speed change operation.

[ means of solving the problems ]

The transmission mechanism of the present invention is constituted in such a manner as to include: a main shaft; a first disc group and a second disc group each including a first disc and a second disc disposed in close proximity to each other in an orthogonal manner to the spindle, and mounted to the spindle at a distance from each other in a facing manner; a plurality of first radial slits and a plurality of second radial slits formed in the first disk and the second disk, respectively; the composite driving wheel comprises a plurality of driving wheels and a plurality of guide rods, wherein the driving wheels comprise chain wheels or pinions, the plurality of guide rods are supported by the crossing parts of a first radial slit and a second radial slit in the first disc group and the second disc group, the composite driving wheel comprises a plurality of driving wheels and a plurality of guide rods, the driving wheels are used for sleeving a chain or a toothed belt for power transmission, the radius of the composite driving wheel can be changed to change the speed by changing the rotation phase of the second disc relative to the first disc, and the speed changing mechanism is characterized in that:

At least one clutch mechanism is provided, which is capable of switching the transmission wheels to a rotation prohibition state and a rotation permission state, and via which the transmission wheels are placed in the rotation permission state during a shift operation and the sprockets are placed in the rotation prohibition state during other than the shift operation.

According to the above configuration, since each of the transmission wheels is set to the rotation permission state at the time of the shifting operation, when the sprocket is used as the transmission wheel, the phase of the sprocket is adapted to the chain, and the permission range of the phase becomes infinite in the shifting range, so that the shifting ratio can be changed to various predetermined transmission ratios even in the rotation stop state. The sprocket is not phase-aligned at the moment of the shifting operation, but is in a phase-aligned state when various predetermined gear ratios are established, so that the noise of collision between the sprocket and the chain is reduced.

Further, since the load torque is blocked during the shifting operation, the shifting can be performed with a small force, and the shifting operation can be performed not only during the forward rotation of the shifting mechanism but also during the reverse rotation or the reverse load state.

Further, since each transmission wheel is set to the rotation prohibiting state at the time other than the shifting operation, torque transmission can be performed via the composite transmission wheel.

The present invention may also take various preferred forms as shown below.

In a first aspect, there is provided: and a phase changing mechanism configured to change a rotational phase of the second disk with respect to the first disk in the first disk group and the second disk group during a shift operation.

In a second aspect, there is provided: and a disc moving mechanism configured to move at least one of the first discs of the first disc group and the second disc group on the clutch mechanism side by a predetermined distance in a direction in which the transmission wheel is placed in a rotation allowable state during a speed change operation.

In a third aspect, the at least one clutch mechanism includes a first dog clutch mechanism and a second dog clutch mechanism disposed on both sides of the drive wheel.

In the fourth aspect, either one of the first dog clutch mechanism and the second dog clutch mechanism is in a half-clutch state during a shift operation, and the transmission wheel is in a rotation prohibiting state when the shift operation is not performed.

In a fifth aspect, first rack teeth are formed in the vicinity of a first radial slit into which the support shaft is inserted in a pair of the first disks of the first disk group and the second disk group, and a first lock mechanism is provided that locks the first rack teeth so that the transmission wheel cannot move in the radial direction of the first disk when the transmission wheel is not in a shift operation, and that allows the sprocket to move in the radial direction of the first disk when the transmission wheel is in a shift operation.

In a sixth aspect, a second rack tooth is formed in a vicinity of a first radial slit into which the guide bar is inserted in a pair of the first disks of the first disk group and the second disk group, and a second lock mechanism is provided that locks the guide bar in cooperation with the second rack tooth so that the guide bar cannot move in the radial direction when not in a shift operation, and that allows the guide bar to move in the radial direction when in a shift operation.

In a seventh aspect, gear teeth are formed on an outer peripheral portion of the first disk of at least one of the first disk group and the second disk group, and a gear member for driving force input or driving force output meshed with the gear teeth is provided.

In an eighth aspect, the at least one clutch mechanism includes a first spline-coupled clutch mechanism and a second spline-coupled clutch mechanism provided on both sides of the transmission wheel.

In a ninth aspect, the transmission wheel is a sprocket, and when changing the radius of the composite sprocket via the phase changing mechanism during a shifting operation, the radius is set so that the outer circumference of the composite sprocket becomes an integer multiple of the pitch of the power transmission chain.

In a tenth aspect, the transmission wheel is a sprocket, and when a radius of the composite sprocket is set at the time of a shifting operation, the sprocket is set in a rotation prohibiting state in a state where an outer circumference of the composite sprocket is set to a phase of the sprocket that is an integer multiple of a pitch of the power transmission chain.

In an eleventh aspect, the transmission wheel is a sprocket, and when a radius of the composite sprocket is set at the time of a shifting operation, a phase of the sprocket, such that an outer circumference of the composite sprocket becomes an integer multiple of a pitch of the power transmission chain, is pulled in by a clutch mechanism in the half-clutch state.

[ Effect of the invention ]

According to the present invention, various effects as described above can be obtained.

Drawings

Fig. 1 is a perspective view of a transmission device according to embodiment 1 of the present invention.

Fig. 2 is a perspective view of the transmission of fig. 1.

Fig. 3 is a perspective view of the essential parts of the tensioner mechanism.

Fig. 4 is a perspective view of the transmission mechanism.

Fig. 5 is a front view of the transmission mechanism.

Fig. 6 is a plan view of the transmission mechanism.

Fig. 7 is a side view of the transmission mechanism.

FIG. 8 is a cross-sectional view taken along line VIII-VIII of FIG. 6.

FIG. 9 is a cross-sectional view taken along line IX-IX of FIG. 6.

Fig. 10 is an exploded perspective view of the essential parts of the transmission mechanism.

Fig. 11 is a structural view of a disc moving mechanism and a phase changing mechanism of the transmission mechanism.

Fig. 12 is a perspective view of the sprocket unit.

Fig. 13 is a front view of the sprocket unit.

Fig. 14 is a perspective view of the sprocket unit.

Fig. 15 is an XV arrow view of fig. 14.

FIG. 16 is a cross-sectional view taken along line XVI-XVI of FIG. 15.

FIG. 17 is a perspective view of the guide bar.

FIG. 18 is a sectional view taken along line XVIII-XVIII of FIG. 17.

Fig. 19 is a perspective view of essential parts of the transmission mechanism of embodiment 2.

Fig. 20 is a perspective view of the sprocket unit.

Fig. 21 is a plan view of the sprocket unit.

FIG. 22 is an XXII arrow view of FIG. 21.

Fig. 23 is an exploded perspective view of one half of the sprocket unit.

FIG. 24 is a perspective view of the guide bar.

Fig. 25 is an exploded perspective view of the first disk.

Fig. 26 is a cross-sectional view of a main part of the transmission mechanism when the sprocket unit is in a connected state.

Fig. 27 is a sectional view of an essential part of the transmission mechanism when the sprocket unit is in the off state.

Detailed Description

The following describes embodiments for carrying out the present invention based on examples.

Example 1

Hereinafter, embodiment 1 of the present invention will be described with reference to the drawings.

As shown in fig. 1 to 2, the transmission T includes two sets of transmission mechanisms 1A and 1B having the same configuration, and a driving force transmission chain 2 (see fig. 8) is provided between the transmission mechanisms 1A and 1B, and a driving force is input to one set of transmission mechanisms 1A and a driving force is output from the other set of transmission mechanisms 1B. As the driving force transmission chain 2, either a roller chain or a toothed chain may be used.

Next, the transmission mechanism 1A will be described.

As shown in fig. 4 to 10, the speed change mechanism 1A includes a base 3, a pair of support columns 4 standing on the base 3, a main shaft 6 supported at both ends by the support columns 4 via bearings 5 (see fig. 11), a first disc group 7A and a second disc group 7B mounted to the main shaft 6 at intervals so as to face each other, four sprocket units 8, and four guide rods 9. In addition, three or more than five sprocket units 8 may be employed. Three or more guide rods 9 may be used. The forward rotation direction of the transmission mechanism 1A is the direction of arrow a shown in fig. 10. The axis X of the spindle 6 is shown as the axis center. In addition, the sprocket in this embodiment corresponds to a transmission wheel, and the composite sprocket corresponds to a composite transmission wheel.

The first disk group 7A and the second disk group 7B include circular first disks 10A and 10B, and circular second disks 11A and 11B, respectively, which are disposed in close proximity to each other in an orthogonal manner to the spindle 6. The width of the first disk 10A in the axial direction X is slightly larger than the width of the first disk 10B in the axial direction, but these first disks 10A and 10B are identical.

The pair of first disks 10A and 10B are disposed on the sprocket unit 8 side in a facing manner, and the pair of second disks 11A and 11B are disposed on the opposite side of the sprocket unit 8 from the first disks 10. The axis X of the spindle 6, the axes of the first disk 10A and the first disk 10B, and the axes of the second disk 11A and the second disk 11B are concentric. The first disk 10A and the first disk 10B are rotatably mounted on the spindle 6 so as to be movable in the axial X direction, and the second disk 11A and the second disk 11B are rotatably mounted on the spindle 6 so as to be movable in the axial X direction.

In the transmission mechanism 1A, the first disk 10A and the first disk 10B are formed so as to have a diameter slightly larger than that of the second disk 11A and the second disk 11B, gear teeth 10A and gear teeth 10B are formed on outer peripheral portions of the pair of first disks 10A and first disks 10B, and a driving force input gear 19a engaged with the gear teeth 10A and the gear teeth 10B is provided, and driving force is input from the outside to the driving force input gear 19a via a clutch mechanism 19 m. Further, the diameter of the driving force input gear 19a may be appropriately set. Further, gear teeth may be formed only on one first disk 10A or first disk 10B, and driving force may be input to only one first disk 10A or first disk 10B.

In the transmission mechanism 1B, gear teeth 10A and 10B are formed on outer peripheral portions of a pair of the first disk 10A and the first disk 10B, and a driving force output gear 19B engaged with the gear teeth 10A and 10B is provided, and driving force is output from the driving force output gear 19B to the outside via a clutch mechanism 19 n. Further, the diameter of the driving force output gear 19b may be appropriately set. Further, gear teeth may be formed only on the first disk 10A or the first disk 10B, and the driving force may be output from only one first disk 10A or the first disk 10B.

Next, the tensioner mechanism 70 that absorbs the slack of the driving force transmission chain 2 will be described. As shown in fig. 1 to 3, a pipe 71 is erected on the base 3 between the support columns 4 on the second disc group 7B side of the transmission mechanism 1A and the transmission mechanism 1B, and the pipe 71 is reinforced by a horizontal reinforcing member 72 erected on the pair of support columns 4. Long holes 71a and 71b are formed in the upper and lower side portions of the pipe 71, and a pair of horizontal shaft members 74 supporting the pair of upper and lower tensioner sprockets 73 are guided from the long holes 71a and 71b into the inside, and coupled to the movable member inside, and the pair of shaft members 74 are pushed to the contact side by a tension spring or a hydraulic cylinder provided inside the pipe 71 via the movable member.

The tensioner mechanism 70 may be omitted, and instead, the position of the transmission mechanism 1B with respect to the base 3 in the lateral direction of fig. 1 may be changed, and the lateral direction interval between the transmission mechanism 1A and the main shaft 6 of the transmission mechanism 1B may be adjusted by automatic or manual fine adjustment.

As shown in fig. 8 to 10, the first disk 10A is formed with a shaft insertion hole 12, four first radial slits 13 corresponding to the four sprocket units 8, and four first radial slits 14 corresponding to the four guide rods 9. The second disk 11A is formed with a shaft insertion hole 15, four second radial slits 16 corresponding to the four sprocket units 8, and four second radial slits 17 corresponding to the four guide rods 9.

The first radial slits 13 and 14 are formed as linear radial slits having a 45 ° difference in direction. On one surface of the first disk 10A on the sprocket unit 8 side, rack teeth 13a and rack teeth 14a are formed near both sides of the linear radial slits 13 and the linear radial slits 14. The width of the rack teeth 13a is greater than the width of the rack teeth 14a. The rack teeth 13a and 14a are rectangular teeth having a pointed front end surface in a side view. The functions of the rack teeth 13a and the rack teeth 14a will be described below.

The second radial slits 16 and 17 of the second disk 11A are curved radial slits intersecting the straight radial slits when viewed from the axial direction, and are formed such that the intersecting angle with the circumferential direction becomes smaller as the line is located outward Zhou Ceyi from the axial direction X. Instead of the curved radial slit, a linear radial slit may be used.

As shown in fig. 8 to 10, in each of the four sprocket units 8, one end portion 20a of the support shaft 20 of the sprocket unit 8 on the first disk group 7A side is supported by an intersection of the linear radial slit 13 and the curved radial slit 16 in the first disk group 7A, and the other end portion 20B of the support shaft 20 is supported by an intersection of the linear radial slit 13 and the curved radial slit 16 in the second disk group 7B.

In each of the four guide rods 9, one end portion 60a of the support shaft 60 of the guide rod 9 is supported by an intersection of the first radial slit 14 and the second radial slit 17 of the first disk group 7A, and the other end portion 60B of the support shaft 60 is supported by an intersection of the first radial slit 14 and the second radial slit 17 of the second disk group 7B (see fig. 18).

The structure is as follows: the composite sprocket S is configured by changing the radial positions of the intersections of the first radial slits 13, 14, the second radial slits 16, and the second radial slits 17 by changing the rotational phases of the second disks 11A, 11B with respect to the first disks 10A, 10B in the first disk group 7A, the second disk group 7B, respectively, and by changing the radial positions of the intersections of the four sprocket units 8 and the four guide rods 9, and by winding the power transmission chain 2 (see fig. 8).

Further, a small diameter portion 6a is formed at the longitudinal center portion of the main shaft 6, and the small diameter portion 6a is used to avoid interference with the teeth of the sprocket 18 when the radius of the composite sprocket S is minimized.

In the shifting operation, in order to connect and disconnect the four first clutch mechanisms 21 and the second clutch mechanisms 22 (see fig. 12 to 16) that switch the operating states of the four sprocket units 8, as shown in fig. 11, a pair of first disks 10A and first disks 10B of the first disk group 7A and second disk group 7B are provided with a disk moving mechanism 40A and a disk moving mechanism 40B that can move in the approaching and separating directions. In addition, in order to change the radius of the composite sprocket S during the shifting operation, a phase changing mechanism 50 is provided that can equally change the rotational phases of the second disks 11A and 11B in the first disk group 7A and the second disk group 7B with respect to the first disks 10A and 10B.

The disc moving mechanism 40A and the disc moving mechanism 40B have the same structure, and therefore the disc moving mechanism 40A will be described. As shown in fig. 10 and 11, the disc moving mechanism 40A includes: a flat slit 41 formed in a predetermined length in the axial direction and penetrating through the spindle 6; an orthogonal pin 42 inserted through the flat slit 41 in an orthogonal manner with respect to the axis, having both ends protruding outward from the surface of the spindle 6, and both ends respectively connected to the inner peripheral wall of the shaft insertion hole 12 of the first disk 10A; a pin introduction hole 43 (see fig. 10) formed in a portion from an end portion side of the main shaft 6 to an axial center side of the main shaft 6, and reaching the flat slit 41; an operating pin 44a slidably introduced into the pin introduction hole 43, and an orthogonal pin 42 is inserted into a through hole 45 at the tip end portion thereof; and a switch actuator 46A for driving the operation pin 44a to move in the axial direction. Further, the disc moving mechanism 40B includes a switch actuator 46B.

When the pair of first disks 10A and 10B are separated by the switch actuator 46A and 46B at the time of the shift operation, the first disks 10A and 10B are brought into the separated open position when the operating pin 44a is moved in the direction of arrow D by the switch actuator 46A, for example, about 5mm, and the operating pin 44B is moved in the direction of arrow F by the switch actuator 46B, for example, about 2 mm.

The switch actuator 46A includes various types of hydraulic cylinders. The hydraulic cylinder includes a piston rod 48 having a piston portion 47, and a cylinder body 49, and a connecting member 48a at the tip of the piston rod 48 is rotatably connected to an annular groove at the end of the operating pin 44 a.

A first oil chamber 49a and a second oil chamber 49b are formed in the cylinder body 49, and when the oil pressure is supplied to the first oil chamber 49a and the oil pressure is discharged from the second oil chamber 49b, the piston rod 48 moves leftward in fig. 11, and when the oil pressure is supplied to the second oil chamber 49b and the oil pressure is discharged from the first oil chamber 49a, the piston rod 48 moves rightward in fig. 11. The hydraulic pressure supply source (not shown) for supplying the hydraulic pressure to the hydraulic cylinder 46A includes a flow rate control mechanism capable of precisely controlling the flow rate of the hydraulic pressure supplied to the hydraulic cylinder 46A, and the hydraulic pressure supply source and the flow rate control mechanism are controlled by the control unit CU. In addition, in the present specification, "oil pressure" means compressed oil.

The connection member 48a at the distal end of the piston rod 48a of the hydraulic cylinder 46B of the disc moving mechanism 40B is connected to the operation pin 44B. The hydraulic cylinders 46A and 46B are examples, and a disc moving mechanism that precisely moves and drives the main shaft in the lateral direction by an electric motor, a gear mechanism, or the like may be used instead of the hydraulic cylinders 46A and 46B.

As shown in fig. 10 and 11, the phase changing mechanism 50 includes a phase changing actuator 52 for driving the spindle 6 to move in the direction of the axis X thereof, a pair of spiral grooves 53 formed symmetrically on the spindle 6 at one end portion and the other end portion of the spindle 6, and a pair of connecting pins 54 having base ends fixed to inner peripheral wall portions of the shaft insertion holes 15 of the pair of second disks 11A and 11B, and tip ends protruding toward the spindle 6 side and engaging with the pair of spiral grooves 53. The spiral groove 53 is formed in a shape such as to rotate about 90 ° when the coupling pin 54 moves 9mm in the axial X direction, for example.

As shown in fig. 9, the pair of coupling pins 54 are fitted in grooves extending in the radial direction of the second disk 11, and are fixed by the pair of screws 54a while engaged with the pair of spiral grooves 53.

The phase change actuator 52 includes a double-acting hydraulic cylinder. The hydraulic cylinder includes a sleeve-shaped piston rod 56 having an annular piston portion 55, and a cylinder body 57. The base end portion of the piston rod 56 includes an annular engagement portion 56a, and the engagement portion 56a is rotatably engaged with an annular groove 58 of the spindle 6.

In the cylinder body 57, a first oil chamber 57a and a second oil chamber 57B are formed on both sides of the annular piston portion 55, and when the oil pressure is supplied to the first oil chamber 57a and the oil pressure of the second oil chamber 57B is discharged, the piston rod 56 and the main shaft 6 move leftward (in the direction of arrow C) in fig. 10 and 11, and the pair of spiral grooves 53 move leftward, so that the second disc 11A and the second disc 11B rotate in the reverse direction with respect to the first disc 10A and the first disc 10B, and the four sprocket units 8 and the guide rod 9 move in the radius reduction side.

In contrast to this, when the hydraulic pressure is supplied to the second oil chamber 37B and the hydraulic pressure of the first oil chamber 57a is discharged, the piston rod 56 and the main shaft 6 move rightward (in the direction of arrow B), and the pair of spiral grooves 53 move rightward (in the direction of arrow B), so that the second disc 11A and the second disc 11B rotate in the normal rotation direction a with respect to the first disc 10A and the first disc 10B, and the four sprocket units 8 and the guide rods 9 move toward the radius-enlarging side.

The hydraulic pressure supply source (not shown) for supplying the hydraulic pressure to the hydraulic cylinder 52 includes a flow rate control mechanism capable of precisely controlling the flow rate of the hydraulic pressure supplied to the hydraulic cylinder 52, and the hydraulic pressure supply source and the flow rate control mechanism are controlled by the control unit CU.

In addition, the hydraulic cylinder 52 is shown as an example, and a phase changing mechanism for precisely moving and driving the spindle 6 in the left-right direction by an electric motor, a gear mechanism, or the like may be used instead of the hydraulic cylinder 52.

The sprocket 18 of the sprocket unit 8 is in the rotation prohibiting state when the shift operation is not performed, and is in the rotation permitting state when the shift operation is performed. Therefore, in order to switch the operating state of the four sprockets 18 during the shifting operation, the first clutch mechanism 21 and the second clutch mechanism 22 are provided at both ends of the sprocket 18 in each of the four sprocket units 8 so as to be attachable/detachable, and the four sprockets 18 are placed in the rotation permission state during the shifting operation and the four sprockets 18 are placed in the rotation prohibition state at the end of the shifting operation via the first clutch mechanism 21 and the second clutch mechanism 22.

Next, the sprocket unit 8 will be described with reference to fig. 12 to 16.

The first clutch mechanism 21 and the second clutch mechanism 22 are dog clutch mechanisms, respectively. The first clutch mechanism 21 includes a first annular portion 23 integrally formed with one end portion of the sprocket 18, a first clutch member 25 fitted to the support shaft 20 so as to face the first annular portion 23, a pair of first clutch teeth 21a and first clutch teeth 21b formed on facing annular surfaces of the first annular portion 23 and the first clutch member 25, and a first spring 26 (compression spring) fitted to an inner concave portion of the first annular portion 23 and the first clutch member 25 and urging the first clutch member 25 to the separation side with respect to the sprocket 18.

The first clutch member 25 is engaged with the linear radial slit 13 of the first disk 10A so as to be capable of radial movement and not capable of rotating by engaging the engaging protrusion 25b protruding to the opposite side of the sprocket 18, and is not capable of rotating all the time. As shown in fig. 15, the sprocket 18 includes, for example, 10 sprocket teeth 18a, and the front ends of the sprocket teeth 18a are formed in a pointed shape toward the radial direction. This is to improve the biting performance with the driving force transmission chain 2. The first clutch teeth 21a and 21b are rectangular teeth having a tip pointed in a side view.

A chamfer portion 25f is formed at an inner diameter side portion of the first clutch member 25. This is to avoid interference with the main shaft 6 while minimizing the radius of the composite sprocket S. The sprocket 18 and the first clutch member 25 are switched as follows: the composite sprocket S is securely locked from radial movement during a shift operation, and the diameter of the composite sprocket S is changed during a shift operation, so that the composite sprocket S can be moved in the radial direction. A locking mechanism 29A is provided for this purpose.

Next, the lock mechanism 29A will be described.

The first clutch member 25 includes: a circular plate portion 25a; an engagement convex portion 25b having a rectangular cross section, protruding from the circular plate portion 25a toward the opposite side of the sprocket 18, is engaged with the linear radial slit 13 at all times, and inhibits rotation of the first clutch member 25; and engaging teeth 25c formed on both sides of the engaging convex portion 25b in the end face of the circular plate portion 25a from which the engaging convex portion 25b protrudes, and which are detachable from the rack teeth 13a on both sides of the linear radial slit 13. The engaging teeth 25c are rectangular teeth having a tip pointed at a lower end in a side view.

In a state in which the first disk 10A corresponding to the first clutch member 25 is moved toward the sprocket 18 by the disk moving mechanism 40A, the first clutch mechanism 21 is in a connected state, the sprocket 18 is in a rotation prohibiting state, and in the lock mechanism 29A, the engaging teeth 25c of the first clutch member 25 are engaged with the rack teeth 13a of the first disk 10A, and a locked state in which movement of the sprocket unit 8 in the radial direction is prohibited is obtained. At the time of the shifting operation, the lock mechanism 29A is released, and the sprocket unit 8 can move in the radial direction.

The first clutch mechanism 21 is an example, and a clutch mechanism other than a dog clutch mechanism capable of transmitting driving force in both forward and reverse directions may be used.

The second clutch mechanism 22 includes a second annular portion 24 integrally formed with the other end portion of the sprocket 18, a second clutch member 27 fitted to the support shaft 20 so as to face the second annular portion 24, a pair of second clutch teeth 22a and second clutch teeth 22b formed on facing annular surfaces of the second annular portion 24 and the second clutch member 27, and a second spring 28 (compression spring) fitted to an inner concave portion of the second clutch member 27 and urging the second clutch member 27 toward the sprocket 18 side with respect to the support shaft 20.

The second clutch member 27 is engaged with the linear radial slit 13 of the first disk 10B so as to be capable of radial movement and not capable of rotating by engaging the engaging convex portion 27B protruding to the opposite side of the sprocket 18, and is not rotatable at all times. The second clutch teeth 22a and 22b are wavy teeth that are wavy in side view.

Between the second annular portion 24 and the second clutch member 27, an annular portion 20c having an enlarged diameter is formed in the support shaft 20, the second annular portion 24 of the sprocket 18 is caught by the annular portion 20c in a state where the second dog clutch 22 is maintained in a connected state, and the second clutch member 27 is caught by the annular portion 20c in a state where the second clutch teeth 22a, 22ba are engaged. In addition, a retainer ring may be used instead of the annular portion 20c.

A chamfer portion 27f is formed on the inner diameter side of the second clutch member 27. This is to avoid interference with the main shaft 6 while minimizing the radius of the composite sprocket S.

The sprocket 18 and the second clutch member 27 are switched as follows: the composite sprocket S is securely locked from radial movement during a shift operation, and the diameter of the composite sprocket S is changed during a shift operation, so that the composite sprocket S can be moved in the radial direction. A locking mechanism 29B is provided for this purpose.

Next, the lock mechanism 29B will be described.

The second clutch member 27 includes: a circular plate portion 27a; an engagement convex portion 27b having a rectangular cross section, protruding from the circular plate portion 27a toward the opposite side of the sprocket 18, is engaged with the linear radial slit 13 at all times, and inhibits rotation of the second clutch member 27; and engaging teeth 27c formed on both sides of the engaging convex portion 27b in the end face of the circular plate portion 27a from which the engaging convex portion 27b protrudes, and which are detachable from the rack teeth 13a on both sides of the linear radiation slit 13. The engaging teeth 27c are rectangular teeth having a tip pointed at a lower end in a side view.

In a state in which the first disk 10B corresponding to the second clutch member 27 is moved toward the sprocket 18 by the disk moving mechanism 40B, the second clutch mechanism 22 maintains the connected state, and in the lock mechanism 29B, the engagement teeth 27c of the second clutch member 27 are engaged with the rack teeth 13a of the first disk 10B, and the second clutch member 27 is locked from being moved in the radial direction. At the time of the shifting operation, the lock mechanism 29B is released, and the sprocket unit 8 can move in the radial direction.

Small diameter portions 20a and 20B are formed at both end portions of the support shaft 20, and the small diameter portions 20a and 20B are inserted into the curved radial slits 16 of the second disks 11A and 11B on the corresponding sides.

The sprocket side end portions of the small diameter portions 20a and 20b are provided with a cushion ring 20m and a cushion ring 20n. The sprocket 18 is rotatably mounted to the support shaft 20 with the first annular portion 23, the second annular portion 24, the first clutch member 25, and the second clutch member 27.

Further, instead of the second clutch mechanism 22, a friction clutch mechanism including one or more friction plates may be employed.

Next, the guide bar 9 will be described.

As shown in fig. 17 and 18, the guide rod 9 includes a support shaft 60, a first engaging member 61, and a second engaging member 62, and the first engaging member 61 and the second engaging member 62 are positioned with respect to the support shaft 60 by a retainer ring 63. A guide portion 64 for engaging the chain 2 is formed between the first engaging member 61 and the second engaging member 62 in the support shaft 60. The first engaging member 61 includes: the body portion 61a has a large width in the circumferential direction of the first disk 10A; and an engagement portion 61b extending from the main body portion 61a toward the first disk 10A and engaged with the linear radial slit 14 of the first disk 10A so as to be free to move in the radial direction and not to rotate.

An engaging tooth 61c is formed on an end surface of the body 61a on the engaging portion 61b side so as to be detachable from the rack teeth 14a on both sides of the linear radial slit 14. The second engaging member 62 includes: the body 62a has a large width in the circumferential direction of the first disk 10B; and an engagement portion 62B extending from the main body portion 62a toward the first disk 10B and engaged with the linear radial slit 14 of the first disk 10B so as to be free to move in the radial direction and not to rotate.

Small diameter portions 60a and 60b having a slightly smaller diameter are formed at both end portions of the support shaft 60, and the small diameter portions 60a are inserted into the curved radial slits 17 of the second disk 11A via washers 65 a. The small diameter portion 60B is inserted into the curved radial slit 17 of the second disk 11B via the washer 65B. Fig. 18 shows a state where the pair of first disks 10A and 10B are separated from each other. As shown in fig. 16, the end of the first clutch member 25 is stopped at a predetermined position by the washer 20m and the second disk 11A.

The end of the second clutch member 27 is caught in a certain position by the washer 20n and the second disc 11B.

As shown in fig. 11, the end of the spindle 6 is supported by the support column 4 via the bearing 5, and a washer 36a is mounted on the spindle 6 between the second disk 11A and the second disk 11B and the bearing 5, and the axial positions of the second disk 11A and the second disk 11B are fixed.

When the first disc 10A is moved to the outside (the disengaging direction) by the disc moving mechanism 40A at the time of the shifting operation, the first clutch mechanism 21 is brought into the disengaged state by the urging force of the first spring 26. When the first disk 10B is moved outward (in the disengaging direction) by the disk moving mechanism 40B, the second clutch mechanism 22 maintains a weak connected state by a relatively weak urging force of the second spring 28, but is in a half-clutch state that is slidable through the wavy teeth.

Therefore, although the sprocket 18 is in the rotation allowed state, the rotation resistance acts by the second spring 28 and the second clutch mechanism 22, and if the rotation torque acts on the sprocket 18, the sprocket rotates in accordance with the torque.

Next, the operation and effects of the transmission mechanism 1A described above will be described.

When the shift operation is not performed (when the shift operation is performed), the first disc 10A and the first disc 10B are at the normal positions where the shift operation is not performed, and the first clutch mechanism 21 and the second clutch mechanism 22 of the sprocket unit 8 are in the connected state, so that the sprocket 18 is in the rotation prohibiting state. In this state, the rotational driving force transmitted from the driving force transmission chain 2 is transmitted to the first disc group 7A and the second disc group 7B via the four sprockets 18 and the four guide rods 9, and the first disc 10A, the first disc 10B, the second disc 11A, and the second disc 11B are reliably rotationally driven.

In the normal operation, since the lock mechanisms 29A and 25c and 27c on both sides of the sprocket 18 are held in the state of being engaged with the rack teeth 13a on both sides of the linear radial slit 13, the position of the sprocket 18 in the radial direction is fixed, and the sprocket 18 does not move in the radial direction, and thus a stable operation state is achieved. In this regard, the four guide rods 9 are also engaged with the rack teeth 14a by the engaging teeth 61c and the engaging teeth 62c, and the radial positions are fixed.

At the time of the shifting operation, either or both of the clutch mechanism 19m and the clutch mechanism 19n are blocked, and are connected at the end of the shifting operation.

In the shifting operation, the disc moving mechanism 40A and the disc moving mechanism 40B are operated to switch the first discs 10A and 10B to the outside (the disengaged position), switch the first clutch mechanism 21 of the sprocket unit 8 to the blocked state, and the second clutch mechanism 22 maintains the half-clutch state, so that the sprocket 18 can rotate. At the same time, the engaging teeth 25c and 27c of the lock mechanisms 29A and 29B are disengaged from the rack teeth 13a on both sides of the linear radial slit 13, and the engaging teeth 61c and 62c of the guide bar 9 are disengaged from the rack teeth 14a on both sides of the linear radial slit 14, so that the plurality of sprocket units 8 and the plurality of guide bars 9 can move in the radial direction.

In this state, when the spindle 6 is moved leftward in fig. 11 by the phase changing mechanism 50, the second disks 11A and 11B are rotated in the reverse direction with respect to the disks 10A and 10B, the radius of the composite sprocket S is switched to the reduced side, and when the spindle 6 is moved rightward in fig. 11, the second disks 11A and 11B are rotated in the normal direction, and the radius of the composite sprocket S is switched to the enlarged side.

The transmission T is not a continuously variable transmission, but a continuously variable transmission that can be shifted in multiple steps (for example, about 60 steps) as will be described below.

Here, consideration should be given to designing the transmission mechanism 1A.

When the radius of the composite sprocket S is switched by the phase changing mechanism 50, when the main shaft 6 rotates once in a state where the chain 2 is wound, the radius needs to be set so that the phase of the sprocket 18 becomes the same phase. That is, the outer circumference of one revolution of the composite sprocket S needs to be an integer multiple of the pitch of the chain 2. This is the case where the adjacent outer circumferences between the adjacent sprockets (including the guide bars) satisfy the following equation.

If let L: adjacent outer perimeter, P: spacing of links, N: number of sprockets 18, m: when the integer L described below is satisfied, the phase of the sprocket 18 becomes the same phase when the composite sprocket S rotates once.

As described in the present embodiment, the number of sprockets 18 is 4 as follows.

L＝P×m+0×P (1a)

L＝P×m+0.25×P (2a)

L＝P×m+0.5×P (3a)

L＝P×m+0.75×P (4a)

When the radius of the composite sprocket S is set so as to satisfy only the expression (1 a), the shift stage is minimized. When the radius of the composite sprocket S is set so as to satisfy the expression (2 a), the shift speed is maximized. Since the sprocket 18 is rotatable during the shifting operation, all of the above equations (1 a) to (4 a) can be adopted.

The pitch between the rack teeth 13a and the rack teeth 14a needs to be set so as to be suitable for the gear stage satisfying the cases (1 a) to (4 a).

In the case of the above formula (1), the adjacent sprocket 18 does not generate a phase difference, but in the case other than the formula (1), the adjacent sprocket 18 generates a phase difference.

The phase difference between adjacent sprockets 18 can be obtained by correlating the above equations (1) to (n) as follows.

If let θ: phase difference of adjacent sprocket 18, a: the number of teeth of sprocket 18, N: the number of sprockets 18

As described in the present embodiment, the number N of sprockets 18 is 4 and the number a of teeth is 10 as follows.

In the case of the above formula (1 a), θ=0° (1 b)

In the case of the above formula (2 a), θ=9° (2 b)

In the case of the above formula (3 a), θ=18° (3 b)

In the case of the above formula (4 a), θ=27° (4 b)

Here, the phase difference between the adjacent sprockets 18 needs to be absorbed via the dog clutch mechanism 21 and the dog clutch mechanism 22, and the pitch angle of the clutch teeth of the dog clutch mechanism 21 and the dog clutch mechanism 22 needs to be set to be the same as the sprocket 18 in the case of the above (1 b), 9 ° in the case of the above (2 b), 18 ° in the case of the above (3 b), and 27 ° in the case of the above (4 b).

When the radius of the composite sprocket S is set at the time of the shifting operation, the control unit CU sets the radius of the composite sprocket S based on the shifting command and the shifting map that is set in advance and in which the radius is set in the manner described above.

As described above, when the main shaft 6 rotates once in a state where the chain 2 is wound, the phase of the sprocket 18 becomes the same phase, and therefore, interference between the teeth of the sprocket 18 and the chain 2 does not occur, and smooth and quiet operation is achieved. Further, at the end of the shifting operation, it is desirable that the shifting operation is ended after the composite sprocket S rotates at least about 180 ° after the shifting operation is completed.

In setting the radius of the composite sprocket S, as described above, the sprocket 18 can be pulled into the phase of the sprocket 18, which is an integral multiple of the pitch of the chain 2, as the outer circumference of the composite sprocket S, by the second clutch mechanism 22 in the half-clutch state.

Further, since the tip of the tooth 18a of the sprocket 18 protrudes, interference between the tooth 18a of the sprocket 18 and the chain 2 does not occur.

Since the gear teeth 10A and 10B for driving force input and output are formed on at least one outer peripheral surface of the first disk 10A and the first disk 10B of the first disk group 7A and the second disk group 7B, the torsional load does not act on the main shaft 6, and therefore the diameter of the main shaft 6 can be made small, and the radius of the composite sprocket S when the composite sprocket S is made the smallest diameter can be reduced, thereby realizing miniaturization of the transmission mechanism 1A.

Example 2

Embodiment 2 of the present invention will be described with reference to fig. 19 to 27.

The transmission mechanism 1C described below may be used instead of the transmission mechanism 1A and the transmission mechanism 1B.

As shown in fig. 19, a main part of the transmission mechanism 1C is that in the transmission mechanism 1C, a spline-coupled clutch mechanism is used as a clutch mechanism of the sprocket unit 70.

As shown in fig. 20 to 23, the sprocket unit 70 has a symmetrical structure along the axial direction with the sprocket 71 interposed therebetween, and therefore a one-sided structure will be described. The same components as those of embodiment 1 are denoted by the same reference numerals, and description thereof is omitted. In addition, the sprocket corresponds to a driving wheel, and the composite sprocket corresponds to a composite driving wheel.

The sprocket unit 70 includes a support shaft 73 formed with a spline shaft portion 72, a sprocket 71 spline-coupled to the spline shaft portion 72, a retainer ring 74 that limits the position of the sprocket 71, a spline member 75, a compression spring 76, a clutch body 77, a clutch member 78, a washer 79, and the like. The clutch member 78 is in contact with the inner surface of the second disk 11A via a washer 79. The support shaft 73 is inserted through the spline member 75, the compression spring 76, the clutch body 77, and the clutch member 78.

The spline member 75 includes a cup-shaped engagement portion 75a having spline teeth 75b formed on the inner surface of the recess, a guide portion 75c having a rectangular cross section, and a rectangular flange 75d. The spline member 75 is spline-coupled to the spline shaft portion 72, and the engagement portion 75a and the spline shaft portion 72 constitute a first clutch mechanism 80. In addition, when the first clutch mechanism 80 is connected, in order to avoid interference between the spline teeth 72a and the spline teeth 75b of the spline shaft portion 72, sharp portions may be formed at the tip ends of the spline teeth 72a and the spline teeth 75 b.

The clutch body 77 includes a circular plate portion 77a, a guide portion 77b having a rectangular cross section protruding from the circular plate portion 77a toward the spline member 75, and clutch teeth 77c formed on the outer front end surface of the circular plate portion 77 a. The clutch member 78 includes clutch teeth 78a engaged with the clutch teeth 77c on the inner front end surface, and the clutch body 77, the clutch member 78, and the compression spring 76 constitute a second clutch mechanism 81. The clutch teeth 77c and 78a are formed as wave-shaped teeth in a side view.

As shown in fig. 25, the first disk 10A includes a disk main body 10m and a divided disk 10n fixed to the inner surface of the disk main body 10m on the sprocket 71 side. The first disk 10 is provided with four first radial slits 82 (first linear radial slits) that guide the sprocket unit 70 to be movable in the radial direction and four first radial slits 83 (first linear radial slits) that guide the four guide rods 90 to be movable in the radial direction at 45 ° intervals.

The first radial slit 82 is formed by a narrow slit portion 82a formed in the dividing disk 10n and a wide slit portion 82b formed in the disk body 10m as a stepped slit, and the narrow slit portion 82a is formed so as to be narrower in width than the wide slit portion 82 b. Rack teeth 13a are formed in the vicinity of both sides of the narrow slit portion 82a in the inner surface of the split disc 10n on the spline 71 side. Further, the rack teeth 13a are rectangular teeth with a tip pointed at the lower end in a side view.

The guide portion 75c of the spline member 75 is fitted to the narrow slit portion 82a formed in the split disc 10n so as to be capable of moving radially and not rotating. When the first disk 10A is assembled, the split disk 10n is coupled to the disk main body 10m by a composite bolt after the guide portion 75c of the spline member 75 is inserted into the narrow slit portion 82a.

Engaging teeth 75e that engage with the rack teeth 13a in the vicinity of both sides of the narrow slit portion 82a are formed in portions on both sides of the guide portion 75c in the end face of the engaging portion 75a of the spline member 75. The flange 75d of the spline member 75 is fitted to the wide slit 82b so as to be radially movable and non-rotatable. Further, the flange 75d cannot pass through the narrow slit portion 82a.

The first disc 10A can be switched to the approaching position shown in fig. 26 and the separating position shown in fig. 27 by the same mechanism as the disc moving mechanism 40A of the embodiment 1. The first disc 10A is kept in the close position except for the shifting operation (during normal operation), and is switched to the separated position during the shifting operation.

In the normal operation, the first disc 10A restricts the position of the spline member 75 to the position on the sprocket 71 side, thereby maintaining the first clutch mechanism 80 in the connected state and the engaging teeth 75e in the engaged state with the rack teeth 13 a. Therefore, the sprocket 71 does not move in the radial direction, and the spline member 75 is kept from rotating at all times.

At the time of the shifting operation, the first disc 10A is switched to the disengaged position moving toward the second disc 11A side, and the spline member 75 is pushed toward the opposite side of the sprocket 71 by the flange 75d, whereby the first clutch mechanism 80 is switched to the blocking state. In this state, the engaging teeth 75e are separated from the rack teeth 13a, and therefore the sprocket unit 70 can move in the radial direction along the first radial slit 82.

The guide portion 77b of the clutch body 77 is fitted to a wide slit portion 82b formed in the disk body 10m so as to be capable of moving radially and not rotating. A D-cut portion 73a is formed at the front end side portion of the support shaft 73, and the D-cut portion 73a is inserted into the clutch member 78, so that the support shaft 73 rotates integrally with the clutch member 78. The spline member 75 and the clutch body 77 are rotatable relative to the support shaft 73.

The compression spring 76 pushes the spline member 75 toward the sprocket 71 side and always pushes the clutch body 77 toward the clutch member 78 side, so that the second clutch mechanism 81 is brought into a connected state. However, since the clutch teeth 77c and 78a of the second clutch mechanism 81 are wave-shaped teeth, the second clutch mechanism 81 is always in the half-clutch state. When the first clutch mechanism 80 is in the blocking state, the clutch member 78 rotates together with the support shaft 73 when a large torque acts on the sprocket 71, whereas the clutch body 77 does not rotate, so that the second clutch mechanism 81 slips.

Next, the guide bar 90 will be described with reference to fig. 24 and 27.

The guide bar 90 includes: the support shaft 91 includes a large diameter shaft portion 91a and a small diameter shaft portion 91b; a pair of regulating members 92 fitted to the large diameter shaft portion 91a of the support shaft 91 and positioned by a retainer 94; and a compression spring 93 that urges these restricting members 92 inward (in a direction of separating from the first disk 10A).

The restricting member 92 includes a restricting portion 92a having an inclined engaging side of the chain and protruding toward the outer diameter side, and a guide portion 92b extending outward in the axial direction from the restricting portion 92 a. Engaging teeth 92c that engage with the rack teeth 14a on both sides of the first radial slit 83 are formed on both side portions of the guide portion 92b in the end surface of the restricting portion 92 a. The rack teeth 14a and the engaging teeth 92c are rectangular gears having pointed tips in a side view.

An engaging portion 91a for engaging the chain 2 is formed between the pair of regulating members 92, and the pair of regulating members 92a protrude outward in diameter to guide the chain 2 to the engaging portion 91a side. The guide portion 92b is inserted into the first radial slit 83 so as to be capable of radial movement and not capable of rotating.

As shown in fig. 25 and 27, the first radial slit 83 is formed as a stepped slit including a wide slit portion 83a, a wide slit portion 83b, and a narrow slit portion 83c, and the narrow slit portion 83c is formed at the opposite side portion of the split disk 10n in the first disk 10A.

As shown in fig. 27, when the first disk 10A is in the approaching position, the engaging teeth 92c engage with the rack teeth 14a on both sides of the first radial slit 14. At the time of the shifting operation, the first disk 10A is switched to the disengaged position, and therefore the engaging teeth 92c are disengaged from the rack teeth 14 a.

When the guide bar 90 is pushed toward the retainer 94 by the urging force of the pair of compression springs 93 and the engaging portion 91a is slightly smaller than the width of the chain 2, the side surface portion of the chain 2 first contacts the inclined surfaces of the pair of restricting members 92a to expand the width of the engaging portion 91a and the chain 2 is engaged with the engaging portion 91a when the chain 2 is engaged with the engaging portion 91a. Therefore, the collision sound at the time of collision of the chain 2 can be reduced.

Next, the operation and effects of the above-described transmission mechanism 1C will be described.

The transmission mechanism 1C also functions in the same manner as the transmission mechanism 1A, and therefore will be described briefly.

At the time of the shift operation, the first clutch mechanism 80 is in the blocking state, the second clutch mechanism 81 is kept in the half-clutch state, and the sprocket unit 71 is in the rotation permission state via the second clutch mechanism 81 in the half-clutch state, and is movable in the radial direction. In this state, the radius of the composite sprocket S can be changed to change the speed ratio. Since the sprocket 71 is in the rotation permission state, the phase of the sprocket 71 is surely adapted to the chain.

When the shift operation is not performed, the sprocket 71 is in the rotation prohibiting state and is firmly in a state of being unable to move in the radial direction. Therefore, the load torque transmitted from the chain 2 can be transmitted reliably, and the transmission efficiency is excellent.

Next, various modifications of the above-described embodiment will be described.

(1) In the above-described transmission mechanisms 1A and 1C, a pinion may be used instead of the sprocket 18 and the sprocket 71, and a toothed belt may be used instead of the power transmission chain 2.

(2) Instead, the second clutch teeth 22a and 22b of the second clutch mechanism 22 may be omitted, and one or a combination of friction surfaces may be formed for frictional contact. In that case, the disc moving mechanism 40B and its accompanying mechanisms may be omitted.

(3) When two sets of transmission units T including the transmission mechanisms 1A and 1B are connected, the transmission mechanisms 1A and 1B can be miniaturized to be compact.

(4) Instead of the wavy clutch teeth of the second clutch mechanism 81, one or a combination of friction surfaces may be provided in the sprocket unit 70.

Further, one of the pair of first clutch mechanisms 80 in the sprocket unit 70 may be omitted. Further, one of the pair of second clutch mechanisms 81 may be omitted.

(5) The sprocket unit 8, the sprocket 18 of the sprocket unit 70, and the sprocket 71 may be arranged in parallel in combination in accordance with the transmission torque.

(6) The gear teeth 10A and 10B of the first disk 10A and 10B may be omitted, and the driving force may be input to and output from the main shaft 6 via the clutch mechanism.

(7) Either one of the clutch mechanism 19m and the clutch mechanism 19n may be omitted.

(8) The first lock mechanism 29A, the second lock mechanism 29B, the clutch mechanism 21, the clutch mechanism 22, the clutch mechanism 80, and the clutch mechanism 81 may be synchronous engagement mechanisms.

(5) In addition, the present invention includes various modifications to the above-described embodiments, which can be implemented by those skilled in the art.

[ description of symbols ]

T: speed variator

S: composite chain wheel

1A, 1B, 1C: speed change mechanism

2: chain for driving force transmission

6: main shaft

7A, 7B: first and second disk sets

8: sprocket unit

9: guide rod

10A, 11A: a first disk and a second disk

10B, 11B: a first disk and a second disk

10a, 10b: gear teeth

13. 14: first radial slit

13a, 14a: first rack teeth, second rack teeth

16. 17: second radial slit

18. 71: sprocket wheel

19a, 19b: gear component

29A, 29B: first locking mechanism, second locking mechanism

21. 22, 80, 81: clutch mechanism

40A, 40B: disc moving mechanism

50: phase change mechanism

80: spline coupling type clutch mechanism

Claims (12)

1. A speed change mechanism constructed in a manner comprising: a main shaft; a first disc group and a second disc group each including a first disc and a second disc disposed in close proximity to each other in an orthogonal manner to the spindle, and mounted to the spindle at a distance from each other in a facing manner; a plurality of first radial slits and a plurality of second radial slits formed in the first disk and the second disk, respectively; and a plurality of driving wheels including chain wheels or pinions, and a plurality of guide rods supported by intersections of the first radial slits and the second radial slits in the first disc group and the second disc group,

The composite driving wheel comprises a plurality of driving wheels, a plurality of guide rods and a chain or a toothed belt for power transmission, the radius of the composite driving wheel can be changed to change speed by changing the rotation phase of the second disc relative to the first disc,

the speed change mechanism is characterized in that:

at least one clutch mechanism is provided, the at least one clutch mechanism can switch each driving wheel into a rotation prohibition state and a rotation permission state,

through the clutch mechanism, each transmission wheel is set to a rotation permission state during a shift operation, and each transmission wheel is set to a rotation prohibition state during other than the shift operation.

2. A gear change mechanism according to claim 1, comprising: and a phase changing mechanism configured to change a rotational phase of the second disk with respect to the first disk in the first disk group and the second disk group during a shift operation.

3. A gear change mechanism according to claim 2, comprising: and a disc moving mechanism configured to move at least one of the first discs of the first disc group and the second disc group on the clutch mechanism side by a predetermined distance in a direction in which the transmission wheel is placed in a rotation allowable state during a speed change operation.

4. A gear change mechanism according to claim 3, wherein: the at least one clutch mechanism comprises a first claw clutch mechanism and a second claw clutch mechanism which are arranged on two sides of the driving wheel.

5. The transmission mechanism according to claim 4, wherein: one of the first dog clutch mechanism and the second dog clutch mechanism is in a half-clutch state during a shift operation, and the transmission wheel is in a rotation prohibiting state when the shift operation is not performed.

6. A gear change mechanism according to claim 3, wherein: first rack teeth are formed in the vicinity of a first radial slit in which the support shaft is inserted in a pair of the first disks of the first disk group and the second disk group,

a first locking mechanism is provided, which locks the drive wheel in cooperation with the first rack teeth so that the drive wheel cannot move in the radial direction of the first disk when not in a shifting operation, and which enables the drive wheel to move in the radial direction of the first disk when in a shifting operation.

7. A gear change mechanism according to claim 3, wherein: second rack teeth are formed at the vicinity of a first radial slit in which the guide bar is inserted in a pair of the first disks of the first disk group and the second disk group,

A second lock mechanism is provided, which locks the guide bar in cooperation with the second rack teeth so that the guide bar cannot move in the radial direction when the shift operation is not performed, and which allows the guide bar to move in the radial direction when the shift operation is performed.

8. A gear change mechanism according to claim 1, wherein: gear teeth are formed on the outer peripheral portion of the first disk of at least one of the first disk group and the second disk group, and a gear member for driving force input or driving force output engaged with the gear teeth is provided.

9. A gear change mechanism according to claim 3, wherein: the at least one clutch mechanism comprises a first spline connection type clutch mechanism and a second spline connection type clutch mechanism which are arranged on two sides of the driving wheel.

10. A gear change mechanism according to claim 1, wherein: the transmission wheel is a sprocket, and when the radius of the composite sprocket is changed via the phase changing mechanism during a shifting operation, the radius is set so that the outer circumference of the composite sprocket becomes an integer multiple of the pitch of the power transmission chain.

11. A gear change mechanism according to claim 1, wherein: the drive wheel is a sprocket, and when the radius of the composite drive wheel is set during a speed change operation, the sprocket is set to a rotation prohibiting state in a state where the outer circumference of the composite drive wheel is set to a phase of the sprocket that is an integer multiple of the pitch of the power transmission chain.

12. The transmission mechanism according to claim 5, wherein: the transmission wheel is a sprocket, and when the radius of the composite sprocket is set during a speed change operation, the phase of the sprocket, in which the outer circumference of the composite sprocket is an integer multiple of the pitch of the power transmission chain, is pulled in by the clutch mechanism in the half-clutch state.